| 摘要 |
PROBLEM TO BE SOLVED: To provide a slice level control circuit in which the stability and the followup ability are compatible with each other adjusting to read-out speed of an optical disk, a state of the optical disk, or the like. SOLUTION: An analog input signal 1a is made to be a C cut RF signal 5a in which a DC component is cut and a DC level is adjusted by a capacitor 2, a resistor 3, and a resistor 4 being connected in series, and voltage applied to one end of the resistor 4. A comparator 6 compares the C cut RF signal 5a with 5b and generates a binarization RF signal 7 being binarization output (binarization data), and the binarization RF signal 7 drives a charge pump circuit 8. An output in which a high frequency component is removed by an analog low pass filter 10 is converted to a digital value for each sampling period by an A/D converter circuit 11, the prescribed filter processing is performed by a digital filter 12, and converted to analog voltage by a D/A converter 13. A slice level of a binarization circuit is controlled by analog voltage outputted from the D/A converter 13. COPYRIGHT: (C)2006,JPO&NCIPI
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